Drill



Sept 6, 1932. cz H.` M. BULL 1,8765041 DRILL Filed Dec. i1, 1928 2 sheets-sneer 1 wmf/.M

C. H. M. BULL sept. 6, waz

DRILL Patented Sept. 6, 1932` UNITED STATES CLINTON H. M. BULL, OF HOUSTON, TEXAS DRILL Application filed December 11, 1928. Serial No. 325,299.

This invention relates to new and usefulV improvements in. a drill.

One object ofthe invention is to provide a novel type of drill of the rotary type y and comprising a head and a detachable '5 blade secured therein and which .may be readily removed therefrom when desired.

Another object of the invention is to provide a rotary drill which includes a drill head, a blade therein having cutting edges, said head being formed to reinforcei or brace the b'l'ade behind the cutting edges thereof, said blade being detachable and novel means in the head for securely locking or anchor ing the blade in the head, when the drill is in use, and for releasing said blade to permit its removal, when desired, as when it becomes necessary to replace a worn blade with -a new one.

A further feature of the invention is to provide a drill of the character described which is composed of a few parts, which is very strong and durable and which is very economical in use due to the fact that when the drill becomes dull, or the blades become broken or worn, new blades can Abe substituted, from time to time, forthe old ones and the head re-used.

With the above and other objects the invention has particular relation to certain novel features of construction, arrangement of parts and use, an example of which is given in this specification and illustrated in the accompanying drawings wherein d lligure l-shows a side view of the complete Figure 2 shows a side view of the blade.

Figure 3 shows a bottom end view of the drill.

' 40 Figure Y4 shows a side view of the .drill head partly in section.

Figure 5 shows an elevational view of the drill and taken at right angles tothe Yview drill,'partly in section, and taken at :right and the blade has the transverse, upwardly Figure 6 shows a side view of the key angles to the' View shown in Figure'4, and Figure 9 shows abottom plan view of the key block. y

Referring now more particularly to the ,y drawings wherein like numerals of reference designate similar parts in each of the figures the numeral l designates the drill head, as a whole, whose upper end is, preferably, reduced forming a shank 2 whose upper end is threaded as at 3 for the attachment .of a drill stem thereto. Opposite side 4, 4, of the head, are tapered downwardly, and the lower end'of the head has a deep transverse blade slot 5, between said tapered sides, extending entirely across said head, and whose upper end is enlarged, forminga mortise, 6. There is a key way 7,through the head, at substantially right angles to the axial plane of the slot 5, provided to receive the key block 8. 4The head, 4beneath this keyway, is 70 congured to present the upper transverse end face 9, and the oppositely disposed, downwardly diverging, side faces 10, 10, with the spaced slots 1l, l1, cut transversely through said faces.

There is a flat blade 12, of a general fish tail type, having oppositely disposed cutting edges, 18, 13. The blade is formed to befitted edgewise into the slot 5 and its upper end has the spacedtenons 14, 14 which iit snugly in the mortise 6 and form locking means between the blade and head. The lower end of the slot 5 is widened forming oppositely disposed, downwardly facing shoulders 15, 15,

v facing shoulders 16, 16, extending entirely across each side thereof,v which abuts the cor responding shoulders 15, when-the blade is in place in the head.

Between the tenons 14 the blade is cut away, to 'provide the key space 17 .which registers with the keyway 7, and the slots 18, 18 which register with the corresponding slotsll, 11, when the blade is in the head.

When the blade is inserted into place the key block 8 is inserted throughfthefkeyway 7 y .and the underside of the key yblock has "the transverse face 9 and the confronting-,idownf head, and said block also is provided with the i lower end extends into the key block 8 and i-s reduced forming the external, annular, downwardly facing shoulder 23, provided to rest against the upper face of said key block 8.

An axial water course 24 leads from the channel 25, of the shaft 2() and continues on down through the key block 8 and through the blade, and at its lower end separates into the discharge ports 26, 26 which discharge the flushing fluid onto the cutting edges at, or near, the center of the bore.

The blade has also the sidecutting, or reaming edges 27, 27 which extend out beyond the head, to ream out the bore as drilling progresses and behind each cutting edge 13 the head has the downward extensions, or braces, 28, 28 whose inner sides present flat faces, as 29, which fit closely against the blade and whose outer sides are cohvex as shown, for

strength. The external surfaces of the key block 8 and filler block 22. conform to the contour of the head so as to give a smooth external contour to the complete drill.

When the parts are assembled the shaft 20 is screwed down so as to force the key block 8 securely in place and the blade Iwill be thereby firmly locked in position. Should the blade become worn out or broken the shaft 20 may be unscrewed until its lower end clears the filler block 22 and said blocks 8 and 22 then removed and the blade taken out and a new one inserted. In this way a head can be used for an indefinite period of time at a great saving of expense and the drill can from time to time be renewed without any considerable loss of time.'

If desired the blade may be additionally `secured in place in the head by means of suitable bolts as 30 which extend through the head and into the .blade as shown. The outer ends of these bolts are housed over by the key block 8 and if the blade should become split apart along a central vertical line, the

parts will be held against dropping into the ore.

The drawings and description illustrate a preferred form of the device but it is to be understood that I do not wish to be limited to the exact form shown and described.

What I claim is:

1. A drill including a head having a blade slot extending transversely therethrough, a

. keyways and slots registering when the blade is assembled with the head, a key block fitted through said aligned keyways and having a 'rib which seats in said aligned slots.

3. A drill including a head having a blade slot therein, a blade in said slot, said head and blade each having a keyway therethrough and each also having a slot, said keyways and slots registering when the blade is assembled with the head, a key block fitted through said aligned keyways and having a rib which seats in said aligned slots, and releasable means through which said block, may be4 secured in interlocking relation with the head and blade.

4. A drill including a headhaving a blade slot therein, a blade fitted into said slot, an interlocking member in the head, said member, blade and head having intermeshing parts which interlock the blade and head, and an axial, locking, screw shaft incorporated into the drill and effective in one position to hold said 'member in such interlocking relation and in another position to permit the release of said member from such interlocking relation, said drill having a water course through said shaft, member, and blade which discharges at the lower end of the drill.

5. A drill including a head having a transverse slot formed with a mortise, a blade fitted into said slot and having a tenon which fits into said mortise, an -interlocking member in the head, said head, -blade andv interlocking member being formed with intermeshing parts, and a shaft incorporated into the drill by threaded connections and effective when in one position to hold said member in such intermeshing position and when in another position to permit the release of said member from such intermeshing position. v

6. A drill including a head having a transverse blade slot, a blade in said slot, a locking member through the head and whose inner end engages the blade, a key member through the head which fits over the? outer end of said locking member and is provided with a rib, said blade having a slot in which said rib seats. i-

7. A drill including a head having a transverse blade slot, a blade in said slot, a locking member through the head and whose inner end engages the bla-de, a key member` through the head which fits over the outer 130 i5 end of, and encloses, said locking member and is provided with a rib, said blade havin a slot in which said rib seats, and axial reeasable means incorporated into the drill and abutting said key member and effective to lock the same in assembled relation with said head and blade.

8. A drill including a head having a transverse blade slot, a blade in said slot, a pair of screws fitted through the head from opposite sides and whose inner ends engage the blade, a key block extending transversely through the head and formed to interlock with the blade and to lit against the outer ends of said set screws, a releasable means for locking said key block in place. 9. lA drill having a head formed with a transverse blade slot, a blade in said slot, said head having a key way therethrough substantially at right angles to said slot said head and blade having registerin slots, said head having downwardly flared aces one on each side beneath said keyway, a key block fitted through saidv keyway and having downwardly flared faces which seat on said faces of said head, said key block being provided with ribs which seat in said registering slots.

10. A drill having alheadformed with a transverse blade slot, a blade in said slot, said head having a key way therethrough substantially at right angles to said slot said head and blade having registering slots, a key block fitted through said key way and provided with ribs which seat in said registering slots, a filler block fitted through saidk key way adjacent the key block and releasable means having a threaded connection with the head and fitted through the filler block and abutting said key block.

l1. A drill including a head having a transverse y blade slot extending entirely therethrough and a key way through the head substantially at right angles to said slot, said keyway having fiared ends forming downwardly diverging faces on the head,

a blade in said slot having a key space which substantially registers with the key way, when the blade is assembled with the head, a key block fitted through said keyway and key space, said key block having diverging aces which fit against the respective head aces.

12. A drill including a head. having a transverse bla-de slot and a key way substantially at right angles to said slot, the head beneath the key way having downwardly diverging faces, a blade in said slot having a key space which substantially registers with the key way, whenthe blade isassembled with the head, a key block fitted through said key way and key space, said key block having diverging faces which fit against the respective head faces, means having a threaded connection with the head and abutting said key block.

13. A drill including a head having a transverse blade slot and a key way substantially at right angles to said'slot, the head beneath the key way having downwardly diverging faces, a. blade in said slot having a key space which substantially, registers with the key way when the blade is assembled with the head, a key block fitted through said key way and key space, said key block having diverging faces which fit against the respective head faces, means having a threaded connection with the head and abutting said key block, said head and blade having registering slots and a rib carried Vby the key block and seated in said registering slots.

14. A drill including a head having a transverse blade slot and a key way substantially at right angles to said slot, the head beneath the key Way having downwardly diverging faces, a blade in said slot having a key space which substantially registers with the key way, when the blade is assem-` bled with the head, a key block fitted through said key way and key space, said key block having dive-rging faces which fit against the respective head faces, means havlng a threaded connection with the head and abutting said key block, said head andblade having registering slots and a. rib carried by the key block and seated in said blade slot.

15. A drill including a head, a detachable blade extending transversely therethrough, a member extending i transversely through the head formed to interlock with the blade, an axial tubular shaft connected with the head movable into one position to hold said member in said interlocking relation and into another position to permit the removal of said interlocking member.

In testimony whereof I have signed my name to this specification.

CLINTON H. M. BULL. 

